1976 drought revealed as worst on record for British butterflies and moths

Posted on 31 May 2017

Scientists at the University of York have revealed that the 1976 drought is the worst extreme event to affect butterflies and moths in the 50 years since detailed records began.

The Adonis blue butterfly (Polyommatus bellargus), a characteristic species of southern chalk downland. Following the drought of 1976, numbers of the Adonis blue crashed after its host plant Horseshoe vetch (Hippocrepis comosa) dried up and caterpillars then starved. Other species with summer-feeding larvae were similarly affected (Photograph credit: David Dennis).

The summer of 1976 saw standpipes in the streets and billions of seven-spot ladybirds swarming in search of food. It was the hottest English summer since records began over 350 years ago - the mercury topped 32 °C for 15 consecutive days across much of southern England, and some regions received no rain for 45 days straight.

Since then, the UK has warmed by a full degree Celsius and experienced numerous bouts of extreme weather, from heavy rainfall and flooding to heatwaves and drought; yet no single year has caused so many butterfly and moth species to crash simultaneously.